Istvan Siró

Polyhydroxyalkanoates (PHAs) for food packaging

Abstract: This chapter addresses the basic and applied characteristics of polyhydroxyalkanoates (PHAs) in the context of their potential future development for food packaging applications. The introduction provides a brief overview of the chemistry and synthesis of PHAs. This is followed by an outline of commercial developments to date and a main section in which the properties of PHAs and PHA-based nanocomposites of greatest relevance to food packaging are discussed. Past research on PHA foams and coatings is outlined and the chapter concludes with a summary as well as possible future trends and suggestions for further reading.

Surface modification of nanofibrillated cellulose films by atmospheric pressure dielectric barrier discharge

A dielectric barrier discharge in a gas mixture of tetrafluoromethane (CF4) and O2 was used for tailoring the surface properties of nanofibrillated cellulose (NFC) films. The surface chemical composition of plasma-modified NFC was characterized by means of X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry, while surface morphology was illustrated by atomic force microscopy. Wettability was characterized through the static sessile drop method. The adhesion between NFC and polylactide (PLA) laminated films was tested by the double cantilever beam technique. As a result of atmospheric pressure plasma treatment, the water contact angle of NFC films increased and the values were comparable with those of PLA films. On the other hand, surface chemical characterization revealed inhomogeneity of the plasma treatment and limited improvement in adhesion between NFC and PLA films. Further research in this direction is required in order to enhance the uniformity of the plasma treatment results.

Nanocomposites for food and beverage packaging

Abstract: The use of polymer nanocomposite materials in food and beverage packaging offers many possibilities for improvements in barrier, mechanical and thermal properties and other important characteristics. As a result, there are already a number of commercial applications and, of particular note, an increasing interest in packaging from renewable materials based on biopolymer nanocomposites. This chapter provides a review of developments in petroleum-based polymer nanocomposites and summarizes the state-of-the-art in terms of R&D on biopolymer nanocomposites, including thermoplastic starch, polylactides, polyhydroxyalkanoates, chitosan, proteins or hemicelluloses in combination with various inorganic or organic nanofillers.